El Camino

Hi everybody:I have here an issue and hopefully somebody can help me.My uncle own an el camino 1967,the guy who sold it told him it is a very special edition because the former owner ordered it to factory with an special engine and some other features like an 7000 rpm tach.My uncle wants to know how special is the vehicle,how many units was build and any other info related to it.We already look on a book but unable to find the complete ref. # stamped on eng. and data plate.The vin # is 136807B114761.The eng. has this #in front VI211FK,the casting #is 3932386.The pistons has .040 stamped on them and has a 4 speeds manual trans.If somebody knows something about this vehicle or knows where to find information it will be greatly apreciated,thanks in advance.Jose.